Method of and machine for producing spiral fin tubing



Mafch 13, 1934. c. w. OWSTON METHOD OF AND MACHINE FOR PRODUCING SPIRALFIN TUBING 6 Sheets-Sheet 1 Filed March 2. 1951 W v M ATTORNEYJ.

March 13, 1934. c. w. owsToN 1,950,623

METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING 6 Sheets-Sheet 2Filed March 2, 1931 INVENTOR. [flaw/E5 W. [7W5/27/7 aw Fm ATTORNEYJ,

March 13, 1934. c. WIOWSTON 1,950,623

METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING Filed March 2.1931 s Sheets-Shef 3 &

INVENTOR.

1755/ /55 fk Z7W5/L/7/7 Q M,4AM,M 54....

ATTORNEYJ'.

March 13, 1934. c, w OWSTON 1,950,623

'METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING Filed March 2,1931 6 Sheets-Sheet 4 INVENTOR. [bar/E5 W Z7W5/0/7 ATTORNEYS.

March 13, 1934.

' c. w. OWSTON 1,950,623

METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING Filed March 2,1931 6 Sheets-Sheet 5 Mum I .Nk/ RM INVENTORV March 13, 19 4, c. OWST'QN1,950,623

METHOD OF AND MACHINE FOR PRODUCING SPIRAL FIN TUBING I Filed March 2,1931 6 Sheets-Sheet 6 1 INVENTOR.

TTORNEYS Patented Mar. 13, 1934 UNITED STATES PATENT OFFICE METHOD OFAND MACHINE FOR PRODUC- iNG SPIRAL FIN TUBING Charles W. Owston,Detroit, Mich., assignor to McCord Radiator & Mfg. 00., Detroit, Mich.,a

corporation of Maine This invention relates to a method of and machinefor producing spiral fin tubing.

One object of my invention is to provide a method and machine wherebythe spiral fin material may be applied to the tube without rotating thelatter.

Another object of my invention is to provide a machine in which thesupply of fin material is rotated asa body about the axis of the tube,thereby permitting the tube to be fed through the machine without beingrevolved.

Another object of myinvention is to have the tube fed longitudinallythrough the machine through the center'of the fin material supply,thereby permitting the fin material to be drawn from the outer or innercircumference of the supply in the application of the fin material tothe tube.

A further object of my invention is to provide a high-speed machinewhereby the fin material may be wound on the tube at a greater speedthan heretofore, thereby increasing the rate of production of themachine.

The invention consists further in the matters hereinafter described andclaimed.

In the accompanying drawings Fig. 1 is a side view, with parts insection, of my improved machine;

Fig. 2 is a rear end view of the machine, with parts in section andparts broken away for the sake of illustration;

Fig. 3 is a top plan view of the machine with parts in section;

Fig. 4 is a front end view of the machine with parts broken away forillustrative purposes;

Fig. 5 is a perspective view of certain of the bearing blocks;

Fig. 6, is a front view of the fin guide;

Fig. 7 is a sectional view taken on line 7-7 of Fig. 6;

Fig. 8 is a similar view taken on line 8-8 of Fig. 6;

Fig. 9 is a perspective view illustrating the direction of movements ofthe gear assembly to be hereinafter described;

Fig. 10 is a view similar to Fig. 4 illustrating the fin strip materialbeing taken from the inner circumference of the reel;

Fig. 11 is an elevational view illustrating the releasable lockingdevice for the removable cover plate to be hereinafter described; I

Figs. 12 and 13 are sectional views taken on lines 12-12 and 13- -13,respectively, of Fig. 11; and

Fig. 14 illustrates the manner in which the fin strip material issqueezed as it is applied to the tube to so change the cross-sectionalshape of the fin strip that it may wind in spiral form about the tube.

In the drawings, 1 indicates the base of the machine, preferably in theform of a table having a top plate 2 and a number of depending legs 3,3.

Arranged on the top plate 2 at the rear end of the machine is a tubefeeding and straightening assembly 4 having a plurality of uprightlaterally spaced standards 5, 5 arranged on opposite sides of themachine and providing vertical guides for bearing blocks 6, 6, in whichare journaled cross shafts 7, 7, as shown in Figs. 1 and 3. Each shaftis provided with a roll 8 having a peripheral groove 9 of a shape toaccommodate a tube 10, which is fed through the machine, and on whichtube-the fin material is spirally wound, as will be hereinafterdescribed.

' Certain of the rolls 8, and thus their shafts '7, are arranged invertical sets along the length of the tube feed, so that a number of therolls engage the upper and lower surfaces, respectively, of the tube 10,as shown in Fig. 1. Thus, the tube 10 is supported in its passagethrough the roll assembly, and with springs associated with the blocksof the rolls, sufficient tension may be placed on the rolls to forcethem into contact with the tube and thus serve to straighten as well asfeed the tube through the machine in the rotation of the rolls in adirection required for the feed. The rolls of the vertical set arepower-driven for this purpose. The form of drive, as shown in thedrawings; is as follows: Sprocket or chain wheels 12, 12, are fixed tothe cross shafts 7 of the lower rolls. These wheels are connected bysuitable power transmitting chains 13, 13, so that the power fur nishedto one of the shafts will rotate the other". In the drawings, I haveshown the power fur-- nished to the lowermost shaft 7, at the inner endof the roll assembly. This shaft is extended beyond one side of the baseor bed of the machine, and is there provided with a sprocket or chainwheel 14, which by a chain or equivalent element 15 is connected -with asprocket or chain wheel 16 on a shaft 1'! mounted in the base of themachine, as shown in Fig. 2. A worm gear 18 is fixed to the shaft 17within the base of the machine, and is in mesh with a worm 19 on a shaft20, which is arranged to extend lengthwise of the machine, and has asprocketor chain wheel 21 engaging a chain 22,

which leads to a chain wheel 23 fixed on a revoluble drum 24 at thefront end of the machine to actuate the fin applying mechanism. Power isfurnished to shaft 20 from a suitable source, as for instance, a lineshaft or an electric motor through drive chain 25 and chain wheel 26 onshaft 20, as shown in Figs. 1 and 2. There may be a suitable clutchdevice 2'7 on shaft 20 in association with wheel 26, whereby the powertothe machine may be cut in and cut off, as desired.

Drum 24 is mounted in anti-friction bearings 28, 29, supported inupright standards 30, 30, on the upper side of the base 1 of the machineat the opposite ends of the drum, as shown in- Fig. 1.

The shaft 7 of the upper roll of each set of rolls in the feedingmechanism is rotated by the lower shaft of the set by being connectedtherewith through intermeshing gears 7, 7 as shown in Fig. 2. Thebearing blocks 6 for the various shafts, as shown in Fig. 5, areprovided with vertical grooves 6 6 on opposite sides thereof to slidablyengage the associated standards 5. The springs 11 for each set of rollsare preferably interposed between the blocks for such rolls. The blockshave suitable recesses 6 6 to accommodate the springs as shown in thedrawings. The springs for the idle rolls bear at their upper endsagainst the bearing blocks for such rolls and at their lower ends Theshaft 20 is journaled in a hanger 31,'

depending from the under side of the top plate 2 of the machine as shownin Figs. 1 and 2. The top plate 2 is provided between the standards 30,30, with an opening 32, so that the chain 22 may extend upward throughthe plate to engage the wheel 23 on the drum 24, as shown in Fig. 3.

A tubular guide 33 is disposed axially of the drum 24, and receives thetube 10 from the feed roll assembly 4 in the operation of the machine.The drum 24 is provided at its front end with an enlarged circulardisk-like head 34, which r0; tates with the drum in the turning of thesame through the chain 22. The head 34 is provided with a centrallydisposed cavity 35, at which the adjacent end of the guide 33 terminatesas shown in Fig. 1 to form a surface against which the fin stripmaterial 36 is pressed in the applying of the material edgewise aboutthe exterior of the tube 10. A revoluble disk 3'7 is associated withthis end of the guide 33, and serves to force the fin strip against theguide in the application of the strip to the tube. It is essential thatthe guide 33 and the disk 37 be revolved in a direction to feed the finstrip material onto the tube. This is accomplished in the followingmanner:

A shaft 38 is journaled in the drum 24 at one side of and in parallelrelation. to the guide 33. The disk 37 is secured to the end of theshaft at the cavity 35. The other end of the shaft is provided with aspur gear 39, which meshes with a similar gear 40 fixed to the guide 33.Gear 40 meshes with a gear 41 loosely mounted on a stud shaft 42 carriedby the drum 24. These gears are at the inner end of the drum and arelocated in a cap-shaped housing 43 which is secured to the adjacentstandard 30. The housing 43 is thus stationary and supports a bushing44, which is locked-against rotation by a nut 45. Bushing 44 is providedwith gear edge of the recess 49.

teeth 46 arranged about the same, with which teeth meshes a gear 47loosely mounted on stud shaft 42. Gears 41 and 47 are preferablyintegrally connected, being made in spool form. As shown in Fig. 9, whenthe drum 24 is revolved in the direction of the arrow a, gear 47 isrolled about the stationary gear 46, and gear 47 is turned in thedirection of the arrow indicated in the figure. Gear 41 is turned bygear 47, and rotates gear 40 in a reverse direction as indicated in Fig.9, thus revolving or turning guide 33 in the same direction as gear 40.The turning of gear 40 turns gear 39 in the direction indicated by thearrow, and through the shaft 38 rotates disk 37 as indicated in Fig. 9,thus causing the fin material fed between disk 37 and guide 33 to bepositively drawn from the fin stock and onto the exterior of the tube10. This is accomplished by having disk 37 set sufiiciently close toguide 33 to frictionally grip the strip between them.

The fin stock is applied to the machine in the form of a fiat reel orcoil 48 as shown in Figs. 2 and 4. This coil is located in an annularrecess or cavity 49 provided in the front face of the disk or head 34 onthe outer side of the same, with a cover plate 50 over the stockmaterial, as shown. The inner circum ference of the coil surrounds anannular flange 51 provided on the head 34 at the base or inner To enablethe coil of fin stock material to revolve bodily with respect to thehead 34, and thus permit a ready and easy drawing of the fin materialfrom the reel, I provide movable supports 52 in the flange 51 for theinner edge of the coil as shown in Fig. 4. These supports are preferablyin the form of rollers located in recesses 53 in the flange 51, theparts being so arranged that the rollers extend slightly beyond theouter periphery of the flange, so as to provide a support for the reel.The axis pins 54 for the rollers 52 are preferably in the form of screwsthreaded in the head 34 on the rear sides of the rollers, as shown inFig. 8. The outer ends of these pins extend through a ring 55 which bythe screws is clamped against the outer side of the flange 51 over theouter ends of the recesses 53 to provide a cover therefor. The inneredge of the cover plate 50 overlaps and is secured to a ring 56 byrivets 57, and said ring is detachably secured to the flange 51 byfastening means to be presently described. The ring 56 has a recess onits inner side to accommodate the ring 55, as shown in Fig. 7.

The flange 51 is cut away at one point in its circumference, as at 59,through which the fin material 36 passes on being drawn from one of thecircumferences of the reel 48, as shown in Figs. 4 and 10. In Fig. 4,the fin material is drawn from the outer circumference of the reel overa roller 60'mounted on the head 34 beyond the outer edge of the reel andin radial alinement with the slot 59. The cover plate 50 is cut away,radially, in line with this slot so that the fin material may be drawnacross the front side of the reel to the guide assembly in the cavity35. To wind the strip material on the tube, it is necessary that thestrip be presented to the tube in edgewise relation thereto, as shown inFig. 6. This makes it necessary therefore that the strip material priorto presentation to the tube be turned into edgewise relation thereto atsome point between the tube and the roller 60-. This is accomplished bytwisting the strip into edgewise relation to the tube just after itleaves the roll 60 and passing the strip-so disposed through a guidechannel or way 61 in the cavity immediately in advance of the pointwhere the strip is presented to the tube for spiral winding thereon. Thechannel 61 is preferably in the form of a longitudinal groove providedin a metal block or bar 62, which is clamped against the bottom face ofthe cavity by cross member 63 through the medium of bolts or screws 64,64, at the opposite ends of the bar as shown in Figs. 6 and 8. The head34 is preferably in the form of a casing of some light material, so asto reduce its weight, and also reduce as much as possible the effect ofthe centrifugal force set up in the rotation of the head, and to providea wearing surface for the fin strip material, as it is fed to the tube10, I provide a hard metalwear strip 65 secured to the head in thecavity opposite the guide strip 62 by a screw 66, as shown in Fig. 8.

The cover plate 50 is detachably secured to the head 34 in the followingmanner: As shown in Fig. 11 the ring 56 is provided with a pair ofdiametrically disposed key slots 6'7, 68, extending through the ring incircumferential di- -rection. Screws 69, '70 extend through therespective slots, and are anchored at their inner of the cover plate.The screw 69 extends outward beyond the ring 56, and provides a slida--ble support for a sleeve '71, within which is a coil spring '72,bearing at its outer end against the under side of the head of thescrew, and at its inner end against the associated end of the sleeve, soas to normally urge the sleeve inward. The larger end of the slot 6'7 isslightly larger than the sleeve '71, so that when the ring has beenturned to register the sleeve with the larger end of the slot, thesleeve will be forced by its spring into the slot, and thus permitremoval of the ring over the sleeve. The screw '70 for the slot 68 hasits head spaced slightly outward from the outer face of the ring 56,and. cooperates with a spring plate 73 secured to the outer surface ofthe ring as shown in Fig. 11. This plate is designed to enter beneaththe head of the screw '70 to aid inholding the ring 56 and its cover onthe head 34. The plate '73 is providedwith a slot or notch '74 toaccommodate the'shank of the screw '70 in the turning of the ring 56'into and out of released position. The enlarged end of the slot 68 islarge enough to permit passage of the head of the screw '70 therethroughwhen the ring 56 has been turned to release position. At such time, thespring 68 are reversely arranged, so that when the ring 56 is turned inone direction the enlarged ends of the slots will be brought intoregister with the head'of the screw '70, and the sleeve '71,respectively, whereas when the ring is turned in the opposite direction,the smaller portions of the slots will be brought opposite the screw andsleeve, respectively. In this position, the ring and its cover arefastened to the head, the coil spring '72 of the sleeve serving to forcethe sleeve against the outer side of the ring across the narrow portionofthe slot 67, while the spring plate '73 by engagement under the headof the screw '70 forces the ring against the head 34. To release thecover plate 50, the

. sleeve '71 is .drawn outward against the tension of the spring '72,whereupon the ring 56 may be turned to register the large portions ofthe slots with the sleeve 71 and head of the screw '70, respectively.

The machine shown and described operates as follows:

To load the machine, the cover plate v is taken off. A reel or coil offin-strip material is then placed in the cavity 49, whereupon the coverplate is re-applied, and fastened in place. The outer end portion of thefin-strip material on the outer circumference of the reel is then drawnover the roller 60, ,twisted and inserted through the guideway' 61,whereupon the strip is drawn partly round the tube 10 which has beenprojected beyond the guide 33. The strip is then tacked, as by solder,to the outer surface of the tube 10, whereupon the machine is set inmotion, and the fin strip rapidly applied on the outside of the tube 10in the form of a sprial, as the head revolves about the axis of 'thetube, and the tube without rotation is fed endwise or longitudinallythrough the machine beyond the head 34. The fin strip is squeezedsumciently or shaped as it passes between the guide 33 and the disk 37to so thin the outer edge portion of the strip that it will readily windon the tube and adjust its outer circumference to the increased lengthprovided by winding the strip edgewise on the tube.

To squeeze the strip to so change its crosssectional shape that thestrip may wind in spiral form about the tube in the operation of themachine, the rear face a: of the disk 3'7, is beveled or inclinedoutward while the opposed end surface y of the guide 33 is straight andsubstantially normal to the axis of the tube or guide as clearly shownin Fig. 14. This provides a triangular-like throat with the apex at theouter end of the throat so as to change the 1 direction to draw thestrip through the throat,

the squeezing or reducing action on the strip is a rolling or rotativeone. This not only aids in drawingthe strip from the supply coil aboutthe tube, but also aids in causing the strip to wind in spiral formabout the tube or adjacent core. Obviously, this squeezing or reducingaction on .the opposite sides of the strip, thins the outeredge portionof the strip so that it will wind in spiral form on the tube as the head3'7 is revolved about the axis of the tube as the tube is fedlongitudinally through the head.

The machine is continued in operation until the supply of fin materialis practically exhausted from the reel, whereupon a new reel is applied,and its outer end either overlapped and brazed to the outwardlyextending end of the previous reel, or run onto the tube and tackedthereto as before described. After the connection has been made, themachine is set in operation and the Winding continues with the fin inthe form of a continuous spiral about the tube. In practice, the tubesrun through the machine are of predetermined lengths. With the machinebeing continuous in its operation, the length of the'tube does notrequire that the machine be stopped, and the fin-strip materialbesevered and then connected with the next tube, because the tubes as theyare fed into the machine may ends through the medium of a suitableclampfixture ('75, Fig. 3), which may be inserted in the bore of thetube and be tightened to connect two tubes together by rotating one withrespect to the other after the clamp has been connected with one ofthem. This, in effect, produces a continuous length of tubing and thefin material may be wound over the joint between the several tubelengths. The tubing with the-fin material Wound thereon is fed out ofthe front end of the machine into a suitable V-shaped trough (not shown)supported at a proper height above the fioor to receive the finishedproduct. The operator to separate the tube lengths need only sever thefin material where it extends over the joints between the tube sections.In this way, a supply of fin material, as carried by the machine, mayhave a lineal length sufiiicient to take care of the several lengths oftubing, without stopping and starting the machine at the beginning andend of each length of tube section. It is only necessary to stop themachine when the coil of fin material becomes exhausted. This stoppingis only momentary because the machine is so constructed that a newsupply may be readily and quickly applied.

Instead of taking the fin strip material 36 from the outer circumferenceof the reel 48, as shown in Fig. 4, the fin strip material may be takenfrom the inner circumference of the reel, as shown in Fig. 10. In thiscase, the fin strip material is led over a roller located in the slot 59in the flange 51. The strip after passing over the roller is twisted soas to enter the guideway 61 for presentation in edgewise relation to thetube 10. The structure of the machine remains the same as before, theonly difference being the location of the guide roll for the fin stripas it passes from the reel to the guideway 61. The fact that it ispossibly easier to make a connection between the fin-strip materialwound on the tube and the outer end of a new reel, makes it preferableto take the feed from the outer circumference of the supply, astheinside of the reel running out may be welded or attached with much moreease to the outside end of the new reel.

The machine of my invention is simple in construction, and is eflicientin operation. The tube itself not being rotated but merely advanced mayhave the rate of feed of the tube so timed as to determine the pitch ofthe spiral wound thereon. In other words, by adjusting the feed, thepitch of the spiral fin may be varied for different jobs. Moreover, themachine carrying its fin supply and revolving it about the axis of thetube enables the machine to operate at relatively high speeds, becausethe drawing of the fin material from the supply is within the speed ofrotation of 'the head 34 of the machine. Thus there is no drag or unduepull on the supply as is likely to be encountered in a machine whereinthe supply is arranged exterior of the rotating parts of the machine,and is not carried by the same. Consequently, with my improved machinethe rate of production may be greatly increased, in that the finmaterial may be applied faster to the tube than heretofore, Then againwith the tube fed merely endwise through the machine, and not revolved,no complicated form of feed and revolving rollers or equivalentmechanism is required inthe drum 24, with the result that the speed ofrotation of the machine is not reduced as when a reducing gearing isrequired to slow down the machine to the feed required for the tubetherethrough. With the machine operating at relatively high speeds andthe tube stationary in so far as rotation is concerned, the fin-stripmaterial may be applied with sufiicient tightness around the exterior ofthe tube to hold it on the tube without the necessity of soldering theparts together as the fin is applied. This has the advantage of-avoidingthe necessity of a solder bath or a solder applying fixture inassociaticn with the machine, thereby allowing such parts to be operatedremote from the machine, and thus enable the machine to produce tubingdevoid of solder, if that type of product is required. Other advantagesof my invention will be apparent to those skilled in the art to which itpertains.

The details of construction and arrangement of parts shown and describedmay be variously changed or modified without departing from the spiritand scope of my invention, except as pointed out in the appended claims.

' I claim as my invention:

1. In a machine for producing spiral fin tubing, a revoluble head havingan axially disposed passage through which a tube may be fed, said headhaving an annular flange about said passage and forming a support for asupply of fin strip material in reel or coil form, said flange having aslot in one part of its circumference whereby the fin strip material maybe drawn from one circumference of the coil through the slot and bepresented to the tube for spiral winding thereon.

2. A machine for producing spiral fin tubing, comprising a revolublehead, a tubular'guide disposed axially of the head and openingtheretlirough, means for feeding a tube through said guide past thehead, means on the head for supporting a supply of fin strip material incoil or reel form about said guide. a rotary disk carried by the headand overlapping with the adjacent end of the guide, means carried by thehead and, acting in the rotation thereof to turn the guide and the diskin a direction to draw the fin strip material from the coil and presentit to the tube for spiral winding thereon, and means for rotating saidhead.

3. A machine for producing spiral fin tubing, comprising a revolublehead, a tubular guide disposed axially of the head and openingtherethrough, means for feeding a tube through the guide past the head,means on the head to support a supply of fin strip material in coil orreel form about the guide, a rotary disk carried by the head andoverlapping the adjacent end of the guide, and means including meshinggears actuated in the rotation of the head for'rotating the guide andthe disk in a direction to draw the fin strip material from the coil andpresent it to the tube for spiral winding thereon," and means forrotating said head.

i. A machine for producing spiral fin tubing, comprising a revolublehead, a tubular guide disposed axially of the head and openingtherethrough, means for feeding a tube through the guide past the head,means on the 'head to support a supply of fin strip material in coil orreel form about the guide, a rotary disk carried by the head andoverlapping the adjacent end of the guide, gearing associated with theguide and the disk for rotating the same in the turning of the head todraw the fin strip material from the coil and presenting it to the tubefor spiral winding thereon, the gearing and the disk being arranged atopposite ends of the guide, and means for rotating the head.

5. A machine for producing spiral fin tubing, comprising a rotary drum,a head fixed to said drum at one end and rotated in unison therewith, atubular guide extending axially through the drum and the head, means forfeeding a tube through the guide past the head, means on the head tosupport a supply ofv fin strip material in coil or reel form about theguide, a rotary disk carried by the head and overlapping the adjacentend of the guide, gearing located at the end of the drum opposite thehead for imparting rotation to the disk and the' guide in the rotationof the drum, and means for rotating the drum.

6. A machine for producing spiral fin tubing, comprising a rotary drum,a head fixed to the drum and rotatable therewith, a tubular guideextending axially through the ,drum and the head, said head having anannular flange about the guide to support a supply of fin-strip materialin coil or reel form and to provide a cavity inside of said flange,means including a roller carried by the head in the cavity formed bysaid flange, and cooperating with said guide for'presenting thefin-strip material in edgewise relation to the tube for spiral windingthereon in the rotation'of the head, and means for rotating the head.

7. In a machine for producing spiral fin tubing, a revoluble head havingan axially disposed passage through which a tube may be fed, said headhaving an annular flange about said passage, a supply of fin stripmaterial carried by the head about said flange in coil or reel form,means carried by the head for drawing the fin strip materialfrom thecoil and presentingit in edge-wise relation to the tube for spiralwinding thereon, a cover for the outer side of the coil,and meansproviding a releasable connection between the cover and the flange, saidmeans being so constructed and arranged that the cover may be attachedto and detached from the flange on'turning the cover in oppositedirections.

8. In a machine for producing spiral fin tubing, a revoluble head havingan axially disposed passage through which a tube may be fed, said headhaving an annular flange about said passage, a supply of fin stripmaterial carried by the head about saidfiange in coil or reel form,means carried by the head for drawing the fin strip material from thecoil and presenting it in edge-wise relation to the tube for spiralwinding thereon, a cover for the outer side of the coil, and meansproviding a pin and slot connection for releasably connecting the coverto the flange.

9. In a machine for producing spiral fin tubing, a revoluble head havingan axially disposed passage through which a tube may be fed, said headhaving an annular flange about said passage and forming a support for asupply of fin strip material in reel or coil form, means carried by thehead for drawing the fin strip material from the coil and presenting itin edgewise relation to the tube for spiral winding thereon, and a coverfor the outer side of the coil and connected to the flange, said flangeand cover being cut away to provide a passage for the feed of the finstrip material from the coil to the tube.

10. The method of making a helical winding for finned tubes or otherpurposes, consisting in revolving a supply of fin strip material in coilform about an axis passing through the coil, drawing the fin stripmaterial from the coil toward said axis, and at the same time soreducing the cross-sectional shape of the strip material that it maywind in successive convolutions in spiral form about said axis upon anadjacent core.

11. The method of making a helical winding for finned tubes or otherpurposes, consisting in revolving a supply of fin strip material in coilform about an axis passing through the coil, drawing the fin stripmaterial from the coil toward said axis, and at the same time presentingthe strip in edgewise relation to said axis and subjecting the strip toa squeezing action from opposite sides to cause the strip to wind insuccessive convolutions in spiral form about said axis in edgewiserelation thereto on an adjacent core.

12. The method of making a helical winding for finned tubes or otherpurposes, consisting in revolving a supply of fin strip material in coilform about an axis passing through the coil, drawing the fin stripmaterial from the coil toward said axis, and at the same time reducingthe cross-sectional shape of the strip by a rolling action applied tothe sides thereto to cause the strip to wind in successive convolutionsin spiral form about said axis on an adjacent core.

13. An apparatus for forming a helical winding from strip metal stock,compressing means for supporting the stock in coil form, means forrevolving the coil about an axis passing through the coil, a pair ofpressure rollers having opposed faces between which the stock passes,and means for rotating said rollers to draw the strip stock from thecoil and so reduce the cross-sectional shape of, the strip stock as itpasses between said rollers to cause the strip to wind in successiveconvolutions in spiral form upon an adjacent core.

14. The method of producing spiral fin tubing, which consists'inrevolving a supply of fin strip? material in coil form about an axispassing through the 'coil, supporting and-feeding a tube through thecoil along said axis without rotating the tube, drawing the fin stripmaterial from the coil and presenting the strip in edgewise relation tothe tube and at the same time so changing the cross-sectional shape ofthe strip that the strip may be wound in spiral form on the tube inedgewise relation thereto as the tube leaves the support. I

15. The method of producing spiral fin tubing, which consists inrevolving a supply of fin strip material in coil form about an axispassing through the coil, supporting and feeding a tube endwise throughthe coil along said axis without rotating the tube, drawing the finstrip material from one circumference of the coil, and presenting thestrip in edge-wise relation to the tube and atthe same time so changingthe crosssectional shape of the strip that it may be wound in spiralform on the tube as the tube leaves the support.

16. The method of producing spiral fin tubing, which consists inrevolving a supply of fin strip material in coil form about an axispassing through the coil, supporting and feeding a tube endwise throughthe coil along said axis without rotating the tube, drawing the finstrip material from the outer circumference of the coil and presentingthe strip in edge-wise relation to the tube and at the same timereducing the thickness of the outer marginal portion of the strip thatit may be wound in spiral form on the tube as the tube leaves thesupport.

17. The method of producing spiral fin tubing, which consists inrevolving a supply of fin strip material in coil form about an axispassing through the coil, supporting and feeding a tube endwise throughthe coil along said axis without rotating the tube, drawing the finstrip material from the inner circumference of the coil and presentingthe strip in edge-wise relation to the tube and at the same time sochanging the crossvsectional shape of the strip that it may be wound inspiral form on the tube as the tube leaves the support. 7

18. In a machine for producing spiral fin tubing, a revoluble head, atubular guide disposed axially of the head and opening therethrough,means for feeding a tube through the guide past the head, means on thehead for supporting a supply of fin strip material in coil or reel formabout the guide, means for rotating the head and the guide about thetube, and means carried by the head and acting in conjunction with therotating guide for drawing the strip material from the coil andpresenting it in edgewise relation to the tube and at the same time soreducing the cross-sectional shape of the strip that it may be wound inspiral form on the tube.

19. In a machine for producing spiral fin tubing, a revoluble head, atubular guide disposed axially of the head and opening therethrough,means for feeding a tube through the guide past the head, means on thehead for supporting a supply of fin strip material in coil or reel formabout the guide, means for rotating the head and the guide about thetube, and means carried by the head and acting in conjunction with theend surface of the rotating guide at the head for drawing the fin stripmaterial from the coil and presenting it in edgewise relation to thetube and at the same time subjecting the strip to a squeezing actionfrom opposite sides :obcause the strip to wind in spiral form on the 20.In a machine for producing spiral fin tubing, a revoluble head, atubular guide disposed axially of the head and opening therethrough,means for feeding a tube through the guide past the head, means on thehead for supporting a supply of fin strip material in coil or reel formabout the guide, means for rotating the head and the guide about thetube, and means carried by the head and acting in conjunction with therotating guide for subjecting the strip as it is presented in edgewiserelation to the tube to a rotative action for drawing the strip from thesupply coil and causing the strip to wind in successive convolutions inspiral form on the tube.

21. In a machine for producing spiral fin tubing, a revoluble head, atubular guide disposed axially of the head and opening therethrough,means for feeding a tube through the guide past the head, means on thehead for supporting a supply of fin strip material in coil or reel formabout the guide, means for rotating the head and the guide about thetube, and means carried by the head and forming in conjunction with theend surface of the guide at the head a triangular throat for the passageof the strip to the tube, whereby the normal rectangular crosssectionalshape of the strip will be changed to conform to the throat for windingthe strip in successive convolutions in spiral form on the tube.

22. In a machine for producing spiral fin tubing, a revoluble head, atubular guide disposed axially of the head and opening therethrough, asupply of fin strip material carried by the head about said guide incoil or reelform, a revoluble support on, the head for the innercircumference of the coil, means for rotating the head and the guideabout the tube, and means carried by the head and acting in conjunctionwith the rotating guide as the tube leaves the same for drawing the finstrip material from the coil and presenting it in edgewise relation tothe tube and at the same time so reducing the crosssectional shape ofthe strip that it may be wound in spiral form on the tube.

CHARLES W. OWSTON.

